Set up a profile. If you haven't already done so, go to the Couch Surfing website and let people know about you. The most important information to include is your location, type of sleeping quarters or "couch" you have available, as well as a limit on how long a surfer can stay.
Get to know your surfer. You should feel comfortable letting this person into your home so always ask questions to find out who they are. If they are trustworthy, they should have no problems with giving you information about where they live and what they do.
Confirm the dates you're available. Your surfer is likely to be flexible and can plan their trip around the host's schedule. Once dates are confirmed, however, stick to them out of courtesy since your surfer may not be able to change their flight or bus schedule.
Make them feel welcome. Your primary purpose as a host is to provide your couch surfer with a place to sleep. However, if you find that you get on well and have the time and desire to act as a tour guide, your surfer may greatly appreciate you for it.
Exchange information. When the time comes for your surfer to leave, be sure to confirm their contact info. This way, you can provide feedback for each other on the Couch Surfing website; letting other users know that you are both trustworthy.